hydraz-
combining form
or hydrazo-
Etymology: International Scientific Vocabulary, from hydrazine
1. : related to hydrazine
 < hydrazide >
2. usually hydrazo- : containing the bivalent radical −NHNH− derived from hydrazine by removal of one hydrogen atom from each nitrogen atom — especially in names of compounds in which the radical is united to two hydrocarbon radicals
 < hydrazotoluene >